Coiled heat exchanger having inserts between the shroud and the last pipe layer

Abstract

A heat exchanger, providing indirect heat transfer between a first fluid and at least one second fluid, comprises a jacket enclosing a jacket space for accommodating the first fluid and a tube bundle arranged in the jacket space and having a plurality of tubes for accommodating the at least one second fluid. The tubes form multiple tube layers. A shroud arranged in the jacket space encloses an outermost tube layer of the tube bundle. Spacers extending along the longitudinal axis are arranged between the shroud and the outermost tube layer. An interspace is present between any two spacers adjacent in the circumferential direction of the shroud, and between the shroud and the uppermost tube layer. A flow obstruction is arranged in the respective interspace and is designed to prevent or suppress a flow of the first fluid in the respective interspace, at least over a part section thereof.

The invention claimed is: 
     
       1. A heat exchanger for the indirect exchange of heat between a first fluid and at least one second fluid comprising:
 a shell which extends along a longitudinal axis and surrounds a shell space for receiving the first fluid, 
 a bundle of tubes, arranged in the shell space, comprising a plurality of tubes for receiving the at least one second fluid, wherein the tubes form a number of tube layers, and 
 a shroud which is arranged in the shell space and encloses an outermost tube layer of the bundle of tubes in the radial direction of the bundle of tubes, 
 wherein spacers that extend along the longitudinal axis are arranged between the shroud and the outermost tube layer, and wherein between every two spacers adjacent to one another in the circumferential direction of the shroud and the shroud and the outermost tube layer there is an intermediate space that extends along the longitudinal axis, 
 wherein a flow obstacle is arranged in each intermediate space and is designed to hinder or suppress a flow of the first fluid in the intermediate space at least over a partial portion of the intermediate space that extends along the longitudinal axis, and wherein each flow obstacle comprises a flexible layer of material, and 
 wherein each intermediate space has a cross-sectional area perpendicularly to the longitudinal axis and a length along the direction of the longitudinal axis, and wherein, along the length in the direction of the longitudinal axis the respective flow obstacle takes up over 50% of the cross-sectional area of the intermediate space. 
 
     
     
       2. The heat exchanger as claimed in  claim 1 , wherein the respective flow obstacle extends in the circumferential direction of the shroud over the entire circumferential extent of the respective intermediate space between the spacers. 
     
     
       3. The heat exchanger as claimed in  claim 1 , wherein the flexible layer of material comprises polytetrafluoroethylene or is formed from polytetrafluoroethylene. 
     
     
       4. The heat exchanger as claimed in  claim 1 , wherein each flow obstacle has a supporting structure. 
     
     
       5. The heat exchanger as claimed in  claim 4 , wherein the supporting structure is formed in the manner of a plate. 
     
     
       6. The heat exchanger as claimed in  claim 4 , wherein the supporting structure comprises a metal or is formed from a metal. 
     
     
       7. The heat exchanger as claimed in  claim 4 , wherein each supporting structure has an upper edge, a front side, and a rear side which faces away from the front side of the supporting structure, and wherein the flexible layer of material is placed or guided around the upper edge of the supporting structure so that the flexible layer of material at least partially covers the upper edge, the rear side and the front side of the supporting structure. 
     
     
       8. The heat exchanger as claimed in  claim 4 , wherein the supporting structure is integrally formed on the flexible layer of material or the flexible layer of material is integrally formed on the supporting structure. 
     
     
       9. The heat exchanger as claimed in  claim 4 , wherein the respective flow obstacle is arranged in the assigned intermediate space with a portion of the flexible layer of material placed or guided around an upper edge of the supporting structure. 
     
     
       10. The heat exchanger as claimed in  claim 4 , wherein the flexible layer of material having a modulus of elasticity in compression in the range from 100 to 1000 MPa. 
     
     
       11. The heat exchanger as claimed in  claim 1 , wherein the respective flow obstacle only extends along a lower portion of the bundle of tubes in the respective intermediate space. 
     
     
       12. The heat exchanger as claimed in  claim 1 , wherein, for forming the tube layers, the tubes are in each case coiled onto a core tube of the heat exchanger that is designed for absorbing the load of the tubes, wherein the heat exchanger has further spacers between the respective tube layer and the tube layer lying thereunder in each case, arranged further inward in the radial direction, wherein said further spacers extend in each case along the longitudinal axis. 
     
     
       13. The heat exchanger as claimed in  claim 1 , wherein the flow obstacle takes up over 60% of the cross-sectional area of the intermediate space. 
     
     
       14. The heat exchanger as claimed in  claim 1 , wherein the respective flow obstacle takes up over 70% of the cross-sectional area of the intermediate space. 
     
     
       15. The heat exchanger as claimed in  claim 1 , wherein respective flow obstacle takes up over 80% of the cross-sectional area of the intermediate space. 
     
     
       16. The heat exchanger as claimed in  claim 1 , wherein respective flow obstacle takes up over 90% of the cross-sectional area of the intermediate space. 
     
     
       17. A method for arranging flow obstacles in a heat exchanger having a shell that extends along a longitudinal axis and surrounds a shell space for receiving a first fluid, wherein the heat exchanger also has a bundle of tubes arranged in the shell space and comprising a plurality of tubes for receiving at least one second fluid, which form a number of tube layers, and a shroud arranged in the shell space and which encloses an outermost tube layer of the bundle of tubes in the radial direction of the bundle of tubes, wherein spacers that are made to extend along the longitudinal axis are arranged between the shroud and the outermost tube layer, wherein between every two spacers adjacent to one another in the circumferential direction of the shroud and the shroud and the outermost tube layer there is an intermediate space,
 said method comprising pushing a flow obstacle into the respective intermediate space, wherein said flow obstacle is designed to hinder or suppress a flow of the first fluid in the respective intermediate space at least over a partial portion of the respective intermediate space that extends along the longitudinal axis, wherein each flow obstacle comprises a flexible layer of material, and 
 wherein each intermediate space has a cross-sectional area perpendicularly to the longitudinal axis and a length along the direction of the longitudinal axis, and wherein, along the length in the direction of the longitudinal axis the respective flow obstacle takes up over 50% of the cross-sectional area of the intermediate space. 
 
     
     
       18. The method as claimed in  claim 17 , wherein the respective flow obstacle has a supporting structure with an upper edge, around which the flexible layer of material is placed, so that a portion of the flexible layer of material surrounds said upper edge, wherein the respective flow obstacle is pushed or guided into the respective intermediate space from below beginning with said portion.